DESCRIPTION (provided by investigator): The Greater Houston area (Harris County, Texas) provides a unique multi-ethnic study area to evaluate effects of air pollution on newborn health and resulting health disparities among racial/ethnic groups. We propose a study of approximately 200,000 births occurring in Harris County between 2005-07, including 49,600 births to foreign-born Hispanic mothers, 32,600 births to U.S. born Hispanic mothers, 35,400 births to African American mothers, 58,800 births to white non-Hispanic mothers and 15,200 births to mothers of other ethnicities. The region's documented poor air quality is influenced by multiple sources of air pollutants due to extensive road traffic and proximity to one of the largest petrochemical industrial complexes in the U.S. Apart from an ongoing study focused on lymphohematopoietic cancer incidence;relatively few investigations have examined health risks in relation to air pollution in this area. A risk assessment commissioned by Houston Mayor Bill White pointed to "definite" health risks associated with ambient air levels of ozone and fine particulates (PM2.5). Moreover, Harris County has been designated a severe non-attainment area for ozone because it exceeds the National Ambient Air Quality Standard for this pollutant. This project addresses a gap in the literature by conducting a population-based study to evaluate associations between preterm birth and intrauterine growth restriction (IUGR) and air pollution in Houston. Preterm birth is a growing public health problem with an etiology that is poorly understood despite sizeable efforts to identify risk factors for this adverse birth outcome. Relative to other pollutants, ozone and PM2.5 have been understudied as risk factors for preterm birth and impaired fetal growth and only one investigation has examined very preterm births, which the proposed study has ample power to study. The considerable seasonal variability in air pollutant levels in this multi-year study will contribute to differential exposures during pregnancy and allow for an evaluation of the effects of these pollutants during different gestational periods. Exposures are also likely to vary by place of residence due to proximity to major point and mobile sources. As the first study to investigate these associations in the area, it will rely upon an efficient and cost-effective study design that will use existing vital statistics and air monitoring data. It will also further evaluate the utility of spatio-temporal modeling of ambient air pollutant levels in environmental epidemiologic research. The specific aims of the investigation are to: 1) estimate maternal exposure to PM2.5 and ozone for each month of pregnancy using non-traditional (spatio-temporal methods) approaches and 2) evaluate the association between maternal exposure to PM2.5 and ozone and risk of preterm birth and IUGR, evaluate whether these associations differ by ethnicity status and determine the proportion of these outcomes that may be attributed to these air pollutants by racial/ethnic groups. The results from this study will assess children's health in the Greater Houston area and provide a benchmark for improving newborn outcomes owing to efforts to reduce air pollution. PUBLIC HEALTH RELEVANCE: The Greater Houston area provides a unique multi-ethnic study area to evaluate effects of air pollution on newborn health and resulting health disparities among racial/ethnic groups. As the first investigation of this kind in the area, this project will conduct a large population-based study to evaluate associations between preterm birth and intrauterine growth restriction (IUGR) and fine particulates (PM2.5) and ozone. The results from this study will assess children's health in the Greater Houston area and provide a benchmark for improving newborn outcomes owing to efforts to reduce air pollution at the at the federal, state and local (city of Houston) levels.